News

Tyre safety, what does it mean?

Tyre safety standards in Australia are being further called
into question following the number of fatalities and serious injuries in the
mining industry. 

Not only the coroners
but also the unions are pointing to a deficiency.

Australia has developed one of the few standards (AS 4457) for
dealing with mining tyres anywhere in the world but injuries and deaths are
still occurring. 

Tyres are composite
flexible pressure vessels. Unlike household
gas cylinders which are rigid steel pressure vessels (like most compressed air
receivers) a tyre has a load placed on it, is rolled over unkind surfaces and
is generally ignored until it goes flat. 

Tyres are specifically excluded from the pressure vessel standard
(AS1210) with OTR tyres (>24” rim diameter) being covered under AS 4457 and
any on road tyres falling under SSection 25 of the Australian Design Rules
(ADR).

When you stop to consider things in detail a tyre is the
only connection between your vehicle and the road. 

The average passenger car requires tyres to
perform steering braking and some minor suspension functions as well as
supporting the load (passengers and baggage).
A giant mining truck tyre is required to support up to 100 tonnes, relying
on the air it contains within to support that load.

If there is insufficient air to support the load the tyre doesn’t
complain or refuse to work like an engine or gearbox. 

It just gets on with the job and literally
tears itself apart performing the function we ask it to do, right up to the
point where it can no longer function and fails, sometimes catastrophically.

Tyres for passenger vehicles have large safety margins
engineered into them during the design phase. 

This is to provide a margin of safety for abuse or lack of attention but
it is of course wiser to keep tyre pressure constantly monitored and the best
way of doing this is to use an automatic pressure monitoring system
(TPMS).

In the US, the TREAD Act mandated
tyre pressure monitoring for all light passenger vehicles manufactured in that
country from 2008 on. 

 The EU followed
suite in 2012, Korea in 2013. The
importance of tyre inflation pressures was mentioned by President Obama last
year. 

He indicated that safety on road
networks is directly affected by poor tyre pressure maintenance, more fuel in
consumed than is necessary thanks to tyres not being maintained correctly as
well as resources being wasted.

To most people tyres are a grudge purchase. They shouldn’t be. 

Tyres are what keeps us safe, keeps our vehicle
on the road performs the steering and braking functions as well as ensuring
comfort. It is not unusual to find that
until a tyre goes flat there is little if any attention paid to it, yet the car
has been washed and polished, the air freshener changed and windows cleaned.

For tyres that work hard (mining and transport) correct
pressure maintenance is even more important.
It is no longer adequate to check tyres when the vehicle has its
periodic maintenance. 

Both the mining
and the transport industries have for many years been monitoring engine oil
pressures using gauges and electronic aids from inside the truck cab, even
transmitting this data to the maintenance office so problems can be identified
prior to failure. 

Tyres on the other
hand are still stuck in the 1950’s using a hand held gauge to check pressures,
well, every so often. 

So how do we tell
what the tyre pressure is when we’re driving down the road? We don’t until it goes flat. 

In 2015 electronic tyre pressure monitoring
is not only feasible but is mandated on passenger cars. Passenger car tyres have an easy life, rarely
carrying their full loads, over-engineered and able to sustain a lot of neglect
and abuse.

Compare air in a tyre to oil in an engine. If the quantity of oil in an engine is not
correct then the engine will wear out faster, overheat and even destroy itself. If a tyre does not have sufficient air it too
will overheat and wear out quickly. 

It
will also consume a lot more fuel as it overheats and then fails, sometimes unfortunately
with disastrous consequences.

A tyre is not just a single piece of rubber but a composite
of many different rubbers all performing a specific function. 

There are steel wires within a tyre that
perform other functions and all need to be operated within the manufacturers
range of recommended inflation pressures.
Like all mobile equipment if it is operated outside of the manufacturer’s
recommended range then failure is probable if not imminent.

Whilst tyres appear simple they are a highly complex engineering
feat. Adhering rubber to steel is a
science all on its own, having certain types of rubber (such as tread rubbers)
remaining hard enough to wear yet flexible enough to roll is another required
attribute.

There are no hard and fast rules to identify issues or
problems with tyres, the easiest suggestion is “if it doesn’t look right it’s
probably not”.

Above all a tyre requires the correct inflation
pressure. 

Every tyre has this same
requirement.

*Adam Gosling heads up TyreSafe Australia who provide guidance to all tyre users. Adam Gosling is a qualified mine manager with knowledge built after more than three decades in tyres.

Leave a Reply

Send this to a friend